1. Field of the Invention
This invention relates generally to phonograph equipment and more particularly to a fluidically supported and fluidically driven turntable for drivably supporting phonograph records, memory disks, or the like.
2. Description of the Prior Art
Conventional turntables are normally supported on a base via a spring-mounting arrangement. The use of such spring-mounting arrangements serves to protect the turntable from shock and vibration external to the instrument, but make no correction for internal mechanical vibrations and rumble and provide no means for compensating for variations in drive speed.
U.S. Pat. Nos. 3,103,364 and 3,674,278 teach phonograph systems wherein the turntable is supported at least partially on a film of air to help isolate the turntable from vibration and mechanical noise. The use of an air bearing provides only a very limited type of vibration isolation and provides no means for compensating for variations in drive speed.
U.S. Pat. Nos. 1,747,866; 1,817,758; and 2,113,390 teach prior art phonograph apparatus wherein the turntable employs some type of flywheel arrangement to compensate for fluctuations in drive speed. Friction is reduced and/or damping action is achieved by the use is a viscuous medium such as oil which may also serve a lubricating function.
U.S. Pat. Nos. 1,778,756 and 2,237,907 teach phonograph apparatus employing a fluid coupling between the drive member and the member carrying the turntable platter, but both patents still involve some type of coupling or bearings constituting a mechanical interconnection between the members, thereby reducing the ability effectiveness of the system to truly isolate the turntable from vibration, rumble and noise caused by the drive means.
U.S. Pat. Nos. 2,221,705; 2,342,414; and 2,557,799 relate generally to fluid couplings but each involves some type of bearing or mechanical interconnection between the driven member and the housing or between the driven member and the drive member thereby increasing the tendency of the system to transmit mechanical vibration and noise.
My co-pending patent application U.S. Ser. No. 721,626 which was filed on Sept. 8, 1976, now U.S. Pat. No. 4,071,252, which issued on Jan. 31, 1978, discloses a FLUIDICALLY DRIVEN TURNTABLE for reducing the undesireable effects of mechanical vibrations and drive speed fluctuations and is incorporated by reference herein. The present invention is a further improvement thereover and further reduces those undesireable effects.
None of these patents teach a true fluid coupling whereby the turntable is totally isolated from the drive means so as to eliminate or at least substantially reduce the undesirable effects resulting from mechanical vibration produced in the bearings and the like. Furthermore, none of these patents teach accomplishing the flywheel effect to compensate for drive speed fluctuation by drivably rotating or circulating a quantity fo liquid within a tank such that the liquid itself drives the actual turntable and forms a part of the flywheel therewith. Yet further, none of these patents teach or even remotely suggest such a fluid coupling wherein the turntable itself is totally supported as well as driven by the fluid so that no mechanical linkage or bearing exists between the driven turntable and the drive member thereby greatly enhancing the ability of this system to eliminate or at least substantially reduce vibration, rumble and noise.
Many of the approaches taught by the prior art involve a deterioration in performance as the parts wear. Most of the prior art systems cannot insure that the turntable is driven with an absolutely constant speed due to motor wear, deterioration of the motor bearings, variations in line voltage, and the like. The mechanical coupling means employed by the systems of the prior art and the springs used to isolate the turntable from vibration and shock meet with only limited or partial success and none is truly capable of isolating the turntable from internal vibration, oscillation and rumble generated within the unit itself.
The present invention provides a turntable which is totally supported by a fluid medium and driven thereby so that the turntable is actually physically isolated from the drive member without any mechanical interconnections, bearings or the like thereby overcoming the disadvantages of the prior art and permitting a vastly more accurate and faithful reproduction of the sounds or information recorded on the phonograph records, memory disks or the like.